The long term objective of this work is to analyze the fluid from the gingival crevice of humans in an attempt to discover a component which can be used to establish criteria for the health status of the periodontium. In this proposal, initial studies on the application of high performance liquid chromatography (hplc) technology to this problem are described. In these studies crevicular fluid will be collected and analyzed by reverse phase and ion exchange hplc for purine nucleobases, nucleosides and nucleotides using techniques previously worked out in this laboratory. Based on preliminary studies, such compounds should present and should show that a correlation exists between pocket depth and the level of phosphorylated nucleosides. The specific aims of the proposal include 1) the continue development of the hplc technology including studies on both stationary and mobile phases, 2) the analysis of samples previously collected to assess reproductability of technique and 3) to analyze samples to explore the problem from saliva, blood and bacteria. It is the intent of this study to apply hplc technology to the problem of periodontal disease by providing clinically-useful guidelines to assess the status of the periodontium.